Semiconductor device

Abstract

Disclosed is a semiconductor device including main and sub-transistors. The main transistor includes: a main channel layer; a main gate electrode located on the main channel layer; a main gate semiconductor layer located between the main channel layer and the main gate electrode; source and drain electrodes located on opposite sides of the main gate electrode and connected to the main channel layer; and a field dispersion layer located on the main channel layer, and located between the main gate and the drain electrodes. The sub-transistor includes: a sub-channel layer including a drift region having two-dimensional electron gas and including a first contact portion connected with the source electrode, a second contact portion connected with the field dispersion layer, and an extension portion connecting the first and second contact portions; and a sub-gate electrode located on the extension portion of the sub-channel layer and connected with the main gate electrode.

What is claimed is: 
     
         1 . A semiconductor device comprising:
 a main transistor including
 a main channel layer, 
 a main gate electrode on the main channel layer, 
 a main gate semiconductor layer between the main channel layer and the main gate electrode, 
 a source electrode and a drain electrode on opposite sides of the main gate electrode and connected to the main channel layer, and 
 a field dispersion layer on the main channel layer, and located between the main gate electrode and the drain electrode; and 
   a sub-transistor connected to a first end of the main transistor, wherein the sub-transistor includes
 a sub-channel layer including a drift region having two-dimensional electron gas, and including a first contact portion connected with the source electrode, a second contact portion connected with the field dispersion layer, and an extension portion connecting the first contact portion and the second contact portion, and 
 a sub-gate electrode located on the extension portion of the sub-channel layer and connected with the main gate electrode. 
   
     
     
         2 . The semiconductor device of  claim 1 , wherein the field dispersion layer and the source electrode are elongated in the same direction, wherein the field dispersion layer is spaced apart from the source electrode. 
     
     
         3 . The semiconductor device of  claim 1 , further comprising:
 a barrier layer between the main channel layer and the main gate semiconductor layer, and including a material having a different energy band gap from the main channel layer; and   a first protective layer covering the main gate electrode and the barrier layer,   wherein the field dispersion layer is on the first protective layer.   
     
     
         4 . The semiconductor device of  claim 3 , wherein the barrier layer and the first protective layer are on the sub-channel layer. 
     
     
         5 . The semiconductor device of  claim 4 , wherein
 the field dispersion layer penetrates the first protective layer and the barrier layer, and is connected to the second contact portion of the sub-channel layer, and   wherein the source electrode penetrates the first protective layer and the barrier layer, and is connected to the first contact portion of the sub-channel layer.   
     
     
         6 . The semiconductor device of  claim 5 , comprising
 a separation structure between the main channel layer and the sub-channel layer,   wherein at least a portion of the field dispersion layer overlaps the separation structure in a thickness direction of the sub-channel layer.   
     
     
         7 . The semiconductor device of  claim 1 , comprising
 a sub-gate semiconductor layer between the sub-channel layer and the sub-gate electrode,   wherein the sub-gate semiconductor layer is in the same layer as the main gate semiconductor layer and includes the same material as the main gate semiconductor layer.   
     
     
         8 . The semiconductor device of  claim 7 , wherein the sub-gate semiconductor layer includes the same material as the main gate semiconductor layer, and
 wherein the main gate electrode and the sub-gate electrode are integrally formed as a single piece.   
     
     
         9 . The semiconductor device of  claim 8 , further comprising
 a separation structure between the main channel layer and the sub-channel layer,   wherein the separation structure is between the sub-gate semiconductor layer and the main gate semiconductor layer.   
     
     
         10 . The semiconductor device of  claim 1 , wherein the main gate electrode and the sub-gate electrode are in the same layer, include the same material, and are integrally formed as a single piece. 
     
     
         11 . The semiconductor device of  claim 1 , wherein the source electrode includes the same material as the field dispersion layer and includes a portion in the same layer as the field dispersion layer. 
     
     
         12 . The semiconductor device of  claim 1 , wherein at least a portion of the field dispersion layer overlaps the sub channer layer in a thickness direction of the sub-channel layer. 
     
     
         13 . The semiconductor device of  claim 1 , wherein the field dispersion layer includes:
 a first field dispersion layer on one side of the gate electrode; and   a second field dispersion layer between the first field dispersion layer and the drain electrode,   wherein each of the first field dispersion layer and the second field dispersion layer is connected to the sub-channel layer and is electrically connected to the source electrode.   
     
     
         14 . The semiconductor device of  claim 13 , further comprising:
 a barrier layer between the main channel layer and the main gate semiconductor layer, and including a material having a different energy band gap from the main channel layer;   a first protective layer covering the main gate electrode and the barrier layer; and   a second protective layer on the first protective layer,   wherein the first field dispersion layer is on the first protective layer, and the second field dispersion layer is on the second protective layer.   
     
     
         15 . The semiconductor device of  claim 14 , wherein the source electrode includes:
 a first source electrode penetrating the first protective layer and on the sub-channel layer; and   a second source electrode penetrating the second protective layer and on the first source electrode,   wherein the first source electrode includes the same material as the first field dispersion layer, and   wherein the second source electrode includes the same material as the second field dispersion layer.   
     
     
         16 . A semiconductor device comprising:
 a main channel layer;   a gate electrode located on the main channel layer;   a gate semiconductor layer between the main channel layer and the gate electrode;   a source electrode and a drain electrode on opposite sides of the gate electrode and connected to the main channel layer;   a field dispersion layer on the main channel layer, and between the gate electrode and the drain electrode; and   a sub-channel layer including a drift region having two-dimensional electron gas, wherein the sub-channel layer includes a first contact portion connected with the source electrode, a second contact portion connected with the field dispersion layer, and an extension portion connecting the first contact portion and the second contact portion,   wherein the gate electrode overlaps the extension portion of the sub-channel layer in a thickness direction of the sub-channel layer.   
     
     
         17 . The semiconductor device of  claim 16 , wherein the field dispersion layer is spaced apart from the source electrode and the gate electrode in a thickness direction with the sub-channel layer. 
     
     
         18 . The semiconductor device of  claim 16 , comprising:
 a barrier layer located between the main channel layer and the gate semiconductor layer and including a material having a different energy band gap from the main channel layer; and   a first protective layer covering the gate electrode and the barrier layer,   wherein the field dispersion layer is on the first protective layer.   
     
     
         19 . The semiconductor device of  claim 18 , wherein the field dispersion layer penetrates the first protective layer and the barrier layer, and is connected to the second contact portion of the sub-channel layer, and
 wherein the source electrode penetrates the first protective layer and the barrier layer, and is connected to the first contact portion of the sub-channel layer.   
     
     
         20 . A semiconductor device comprising:
 a main transistor including a main channel layer including GaN,
 a barrier layer on the main channel layer and including AlGaN, 
 a main gate electrode on the barrier layer, 
 a main gate semiconductor layer between the main channel layer and the main gate electrode and including GaN doped with p-type impurities, 
 a source electrode and a drain electrode on opposite sides of the main gate electrode and connected to the main channel layer, 
 a first protective layer on the main gate electrode and the barrier layer, and 
 a field dispersion layer on the first protective layer, and between the main gate electrode and the drain electrode; and 
   a sub-transistor connected to a first end of the main transistor, wherein the sub-transistor includes:
 a sub-channel layer on one side of the main channel layer, including the same material as the main channel layer, and including a first contact portion penetrating the barrier layer to be connected with the source electrode, a second contact portion penetrating the first protective layer and the barrier layer to be connected with the field dispersion layer, and an extension portion connecting the first contact portion and the second contact portion, and 
 a sub-gate electrode on the extension portion of the sub-channel layer, connected to the main gate electrode, and including the same material as the main gate electrode.